Windshield towels



United States Patent ABSTRACT OF THE DISCLOSURE- This invention relates to a 2-ply paper towel useful for cleaning windows and the like. The towel is madeof a detergent-containing ply and a nondetergent ply of absorbent paper. The detergent is substantially uniformly impregnated into the detergent-containing ply, which is used to loosen dirt and other foreign matter from a wetted window for subsequent removal by the absorbent ply.

This invention relates to an improved composite 2-ply window towel and a method for making one of the plies. In particular, the invention relates to an improved 2-ply towel particularly useful for cleaning and drying windows such as automobile Windshields, oneply of such towel containing detergent, the other being free of detergent and the invention further relates particularly to an improved method for making the detergent-containing ply of such towel.

It is well known in the art to make 2-ply windshield paper towels from two sheets of plain highly absorbent wet strength paper. Generally, water or an alcohol-detergent-water solution is used in conjunction with these towels to remove dirt, road film, etc., from windows, particularly automobile Windshields. The alcohol-detergentwater solution cleans the windows more easily than water alone due to the solutions ability to loosen and emulsify dirt and oil. Use of 2-ply paper adds strength and absorbency and permits a longer use of the cleaning towel.

Cleaning solution is normally applied to a dirty windshield by means of a spray applicator, e.g., a manually operated atomizer. Such devices, however, plugged and need refilling often, which has led many users to the use of plain water rather than a cleaning solution.

To eliminate the need for special cleaning solutions, there are known windshield towels which have a detergent or abrasive cleaning aid of some kind applied to either both sides of a single ply towel or to both plies of a 2-ply towel. In the use of such towels, the surface to be cleaned is wetted with water and rubbed with the detergent-containing towel. During the rubbing, detergent or other cleaning material is transferred from the towel to the window as may be evidenced by suds which are characteristic of certain detergents. One serious drawback of such a towel is that detergent is applied to either both sides of a single ply or to both plies of a 2-p ly towel which makes it difficult to remove the detergent from the window using the same towel. Thus, the detergent, depending upon its physical and chemical characteristics, may leave a film or haze on the window thus causing a reduction in visibility.

It is also well known in the art to incorporate detergent or other cleaning material into paper toweling by spraying an aqueous solution of the detergent on the paper at some point in the papermaking process or by dipping or by soaking the paper in a detergent-containing solution. The spray technique is satisfactory except that the detergent, if applied while the paper is newly formed and wet, interferes with the formation of the fiber bonds causing a decrease in paper strength, particularly wet strength. Dipping or soaking is also satisfactory if the amount of become 3,393,417 Patented July 23, 1968 absorbed or coated detergent is carefully controlled, otherwise the paper may ultimately contain too much detergent to be economical and also so much that in use, haze forms on the window to be cleaned from excess detergent. i

It is therefore an object of this invention to provide a window cleaning towel which is economicaland simple tornake and which can be used to wash and dry a window without the use of separate powder or liquid detergent material.

It is a further object of this invention to provide a 2-ply window cleaning towel, one ply of which contains detergent material, which towel can be used effectively to clean a WlIldOW or windshield and leave no detergent haze or film on the window or windshield.

, It is a further object of this invention to provide a process for making a detergent-containing towel for use as one ply of a 2-ply windshield cleaning towel whereby the detergent-containing ply has good wet strength and contains suflicient detergent to clean effectively but not an excess of detergent which would make the towel uneconomical or leave a haze or film on the window to be cleaned.

Other objects of the invention will become apparent as the invention is described hereinafter.

The objects of our invention are achieved by providing a 2-ply paper towel to which detergent has been applied to only one ply which, when wetted, will liberate the detergent on the surface to be cleaned. The other ply is not treated with detergent and therefore can be used to dry a window or windshield removing excess detergent, dirt and water from the window or windshield. By constructing the towel from a combination of a detergentcontaining ply and a nondetergent-containing ply, it is possible for a user to clean a wetted window with one side of the towel and turn the towel over for removal of detergent and dirt with the other side. In this way it is not necessary for a user to maintain a separate supply of liquid or powder detergent, nor must a user maintain separate supplies of detergent-containing and, nondetergentcontaining towels. We have found that our 2-ply towel having detergent in one ply gives the towel greater service life than a towel with detergent on both plies. Thus in the towel of our invention, the nondetergent ply of the towel is used to wipe detergent off the windshield, there-by eliminating haze and film. On the other hand, a detergent towel having both plies impregnated with detergent continuously applies detergent regardless of which way the towel is turned.

The 2-ply paper toweling of our invention is made on conventional papermaking equipment and the production of the absorbent paper stock per se forms no part of our invention. Basically, the paper is made, as is well known in the art, on a Fourdrinier wire, then passed through wet press and dryer sections into reels from which rolls are made. The two plies which rrnake up the composite towel of our invention are put into face-to-face contact off of separate rolls and then cut and packaged as towels as is conventional in the art. Detergent is added to one ply during the paper-making process as is hereinafter described. We prefer to add the detergent to a 23-lb. per ream paper (24" x 36" 500 sheet basis) which becomes the detergent ply. The nondetergent ply is 31-lb. per ream paper (24" x 36" 500 sheet basis), thus giving the towel greater drying power and longer life.

We have found that the detergent is most effectively applied to the detergent-containing ply of the towel by spraying an aqueous solution of detergent onto the paper, although other coating techniques can be used. Although the detergent can be sprayed onto the paper at any point after the paper has been formed on a Fourdrinier wire, well known in the papermaking art, we prefer to apply. the detergent after the fiber bonds of the paper are formed to minimize the interference by the detergent with the formation of strong bonds. On the other hand, the detergent should preferably be applied while there is sufiicient drying capacity left in the papermaking process to remove any water which is added in conjunction with the detergent. Thus the exact location where detergent is applied is determined by two factors, the first being that the paper should be sufiiciently formed and dried to minimize the effect the detergent has in interfering with wet strength development of fiber bonds; and secondly, that there should be sufficient drying capacity available after the detergents application to remove water added in conjunction with the detergent.

We prefer to spray detergent onto the paper after it has left the wet press section of a papermaking machine at some point located in the dryer section where the paper meets the requirements listed above. It should be understood, however, that the detergent may be sprayed at any desirable point after initial formation of the paper on a Fourdrinier wire including positions on the wire after the suction boxes. The spray equipment used may be any conventional spray nozzle and we prefer to arrange the nozzles in a spray bank to cover the entire web of paper going through the machine. In one embodiment, we arrange one sprayer bank immediately ahead of a section of 4-foot dryers and in others immediately before the last dryer of the machine and in the dryer section of the machine. We have attempted to apply the detergent on the wet end of the machine at the felt position of the wet presses. However, excessive foaming was encountered. But for the foaming, this would be the ideal point to apply detergent.

The temperature at which the detergent is applied to the paper is determined primarily by the solubility of the detergent in water and can range from 70 F. to 200 F. In one particular application, the detergent was added to water and mixed at a temperature of about 125 F. This proved satisfactory for solutions having a detergent content up to about 25%. For applying to the paper, the solution is permitted to reach ambient temperature. However, the solution can be applied to the paper at any temperature at which the detergent is in solution, e.g. between 80 F. to 125 F.

Any commercially available detergent suitable for washing glass can be used in conjunction with our invention, e.g., ethoxylated alkyl phenols, sulfated ethoxylated alkyl phenols, alcohol sulfates, ethyoxylated alcohol sulfates of ethoxylated alcohols and taurates. We prefer to use detergents which are anionic because our work has shown that such detergents do not leave a film; cationic and nonionic detergents could be used if they foamed sufiiciently and did not leave a film.

In particular, we have found that ammonium salts of a sulfated alkyl phenoxypoly (ethyleneoxy) ethanol are particularly good detergents, since they clean well and leave substantially no haze or film on the glass. In our process we have applied the detergent to the paper from an aqueous solution which after drying provides paper with concentrations of from 1.0 to 2.5% detergent by weight. Such concentrations give excellent foaming and detergency action and provide substantially no haze formation on the finally cleaned window.

As can be seen from the above description of our invention, we provide a 2-ply towel which can easily and effectively be used without the necessity of additional liquid or powder detergent to clean and dry a window or windshield without leaving any objectionable haze or film. In using a 2-ply towel, it is possible to absorb more water and dirt from a dirty windshield or window than is possible by using two single-ply towels separately. That is, a 2-ply towel can absorb per given area generally two and a half to three times more liquid and dirt than two singleply towels can absorb, the difference being that the two plies not only themselves absorb liquid material but also hold material between the plies in sandwich-like config uration. This means it is possible to use a greater quantity of water ona window or windshield for effective cleaning when rubbing with the detergent ply and yet be able to remove all the water, dirt and excess detergent by turning the towel over and rubbing with the nondetergent-containiug ply. This is important since it is essential to remove all water and haze from the window prior to drying.

We prefer to emboss each ply so that the plies are held together loosely by mating of the embossed surfaces. This aids in keeping both plies of the paper together during handling and normal cleaning use. In addition, the plies are held together with pins during cutting; these pins puncture the two plies which aids in holding them together. If desired, spot quantities of any paper adhesive could be applied to the mating surfaces of the plies so that the plies are held together positively during handling and later use.

Those skilled in the art will recognize certain modifications which can be made in our invention being within the scope thereof and we intend that our invention be .limited solely by the appended claims.

We claim:

1. A 2-ply paper towel useful for cleaning windows and the like comprising a detergent-containing ply and nondetergent-containing ply of absorbent paper, said plys being disposed in face-to-face contact with one another, both of said plys being made from substantially the same absorbent paper, said detergent-containing ply having sufficient detergent impregnated therein to loosen dirt and other foreign matter from a wetted surface for subsequent removal by said nondetergent-containing ply when said detergent-containing ply is rubbed against said surface, but an insufiicient amount of detergent to leave a film or haze on said surface after application to said surface of said nondetergent-containing ply, said detergent-containing ply being impregnated substantially uniformly throughout its entire surface area with said detergent.

2. The towel of claim 1 wherein the detergent in said detergent-containing ply is an anionic detergent.

3. The paper towel of claim 1 wherein said detergentcontaining ply contains 1 to 2.5% by weight of detergent.

4. The towel of claim 1 wherein said detergent is an ammonium salt of a sulfated alkyl phenoxypoly (ethyleneoxy) ethanol.

5. The towel of claim 1 wherein said detergent-containing ply possesses wet strength developed by having said detergent applied to said ply after said ply of paper has been sufliciently formed and dried to develop fiberbonds but before said ply of paper has been completely dried so that remaining drying capacity of said ply of paper assists the removal of solvent in said applied detergent.

References Cited UNITED STATES PATENTS 1,868,862 7/1932 VVashburn 15506 3,121,249 2/1964 Affleck et al. l5506 3,293,683 12/1966 Wyant 15506 3,304,264 2/1967 Durbin et al 252152 XR CHARLES A. WILLMUTH, Primary Examiner.

ROBERT L. BLEUTGE, Assistant Examiner. 

